The present invention relates to the manufacture of reinforcing preforms for structural composites, and more particularly to optimizing the use of robotic systems in the manufacturing process.
The present invention relates to methods and systems for making rigid three-dimensional reinforcement preforms used in resin transfer molding (RTM) and structural reaction injection molding (SRIM) processes for the manufacture of structural composites. The manufacture and use of structural composite materials is becoming increasingly important today, particularly in components for the automotive industry. Structural composites are lighter in weight than conventional steel or metal components and can result in additional advantages, such as allowing fully automated, highly controllable processes, better part-to-part consistency, reduced waste or scrap, and equivalent or increased component performance.
In general, the structural reinforcing preforms are made from a sprayed chopped material, such as glass and carbon fiber, which is held together by a binder and molded into a precise form and shape. The preform in turn is then molded into products, such as composite components and used in automobiles or other vehicles.
The preform material is chopped and applied along with a powdered binder to a preform screen in a mold using a robotic routine. Positive air flow through the screen holds the chopped material on the screen surface. When the spraying is completed, the mold is closed and the preform is compressed to the desired thickness. Heated air is first drawn through the screen in order to melt the binder. Thereafter, cooled or ambient air is drawn through the preform setting the final shape. Once the preform is completed, it is demolded and transferred to a component mold where the structural component is molded.
Although present automated preform processes and systems have been used to produce satisfactory structural composite products, a need exists to improve the processes and systems, particularly to reduce the cost, increase the output and reliability, and make components of various configurations and thicknesses.
It is an object of the present invention to provide improved systems and processes for making rigid three-dimensional reinforcement preforms for resin transfer molding (RIM) and structural reaction injection molding (SRIM) processes for composite components and products.
It is also a object of the present invention to provide greater flexibility and reach for the robotic system. It is another object of the present invention to provide an additional robot axis and to allow use of a single robot in a multiple cell system.
It is another object of the present invention to improve the process for programming the robotic system for making preforms, including reducing the time for generating the program routines.
It is still another object of the present invention to utilize robotic programming systems offline in order to reduce the use of the actual manufacturing equipment and down time of the manufacturing system.
In accordance with these objects, the present invention provides improvements and advantages over known preform processes and systems. With the present invention, a single robot can be used with a dual cell system. An additional robot axis is used for greater flexibility and reach of the robot. The robot is allowed to move between cells in order to apply the chopped materials and binder in one cell while the applied materials are being consolidated in the other cell.
The program for the robotic equipment used to apply the chopped materials and binder is automatically generated. The program is also generated offline in order to prevent use of the actual manufacturing equipment during the programming process. Software programs can be utilized to program the robot offline, reducing the down time of the manufacturing operation.